Process for the production of triaryl organoborates

ABSTRACT

The invention relates to a process for preparing triaryl organoborates proceeding from alkyl or cycloalkyl boronates in the presence of an n-valent cation 1/n Kn+ and to the use of these substances as co-initiator in photopolymer formulations.

The invention relates to a process for preparing triaryl organoborates proceeding from organoboronic esters in the presence of an n-valent cation 1/n K^(n) and to the use of these substances as co-initiator in photopolymer formulations.

Triaryl organoborates, together with suitable sensitizers, for example cationic, anionic or uncharged dyes, can form type (II) photoinitiators that trigger free-radical photopolymerization of suitable monomers via actinic radiation. The preparation thereof has been widely described, and selected tetraalkylammonium triaryl(alkyl)borates are commercially available.

DE 198 50 139 A1 describes the synthesis of tetraalkylammonium triaryl(alkyl)borates proceeding from an alkyl or cycloalkyl boronate, and the reaction thereof with three equivalents of an organometallic reagent, especially a Grignard reagent. In a first step, the alkyl or cycloalkyl boronate is prepared and isolated, and this alkyl or cycloalkyl boronate is then reacted with a separately prepared organometallic reagent, generally a Grignard reagent. In a third step, the triaryl(alkyl)borate thus formed is precipitated in salt form by addition of a tetraalkylammonium compound and purified, for example by crystallization. There are thus a total of 3 synthesis stages for preparation of tetraalkylammonium triaryl(alkyl)borates. Since the solubility of organometallic reagents, especially Grignard reagents, in the ethereal solvents that are typically used is limited, it is necessary in this process, especially at the organometallic reagent stage, to work in quite dilute solution in order to keep all the ingredients homogeneously in solution. The solubility of Grignard reagents in tetrahydrofuran or diethyl ether, which are the ethers typically used, is typically 1 to 2 mol per litre. Since, however, three equivalents of Grignard reagent are required owing to the stoichiometry, the target concentration of product is one third of this value, meaning that the solubility of the Grignard reagent defines the target concentration. An optimized space-time yield is an important aim for industrial application. However, this can be achieved only to a limited degree by the process described in DE 198 50 139 A1.

JP2002-226486 A describes the synthesis of ammonium and phosphonium triaryl(alkyl)borates proceeding from an alkyl or cycloalkyl boronate and the reaction thereof with three equivalents of an organometallic reagent, especially a Grignard reagent, by an in situ method (Barbier), in which the organometallic reagent is generated in the presence of the electrophilic alkyl or cycloalkyl boronate. In this way, it is possible to achieve higher space-time yields, and the exothermicity of the organometallic stage can thus be better controlled. Furthermore, some reactive organometallic reagents are only of limited storage stability and have to be protected from water or atmospheric oxygen at great cost and inconvenience, since they are otherwise hydrolysed or oxidized, which in turn reduces the overall yield.

However, both processes described above still require the addition of the selected cation in a further reaction step. It is advantageous for an economically viable preparation on the industrial scale when the cation chosen is already present in the preparation of the triaryl organoborate, because a further reaction step is thus dispensed with and the procedure and workup can be made more efficient. Moreover, the concentration of the reagents can be increased further, since the metal-arylammonium salts that otherwise occur in the solvents used are only of limited solubility and prevent control over the reaction enthalpy through voluminous precipitates.

The problem addressed by the present invention was therefore that of providing a process for preparing triaryl organoborates, in which an improved space-time yield leads to better economic viability.

This object was achieved in accordance with the invention by a process for preparing triaryl organoborates of the formula 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV), where one equivalent of organoboronic ester of the formula B—R¹(OR²)(OR³) (I) is initially charged together with 1/n equivalents of salt K^(n+)nX⁻ (II) and 3 equivalents of metal M in a solvent or a solvent mixture S, 3 equivalents of a haloaromatic R⁴—Y (III) are added, and optionally a second organic solvent water S is added and the compound 1/n K^(n+) R₃ ⁴B⁻—R¹ (IV) is separated off with the organic phase,

in which

-   -   R¹ is an optionally hydroxyl- and/or alkoxy- and/or acyloxy-         and/or halogen-substituted C₁- to C₂₂-alkyl, C₃- to C₂-alkenyl,         C₃- to C₂₂-alkynyl, C₅- to C₇-cycloalkyl or C₇- to C₁₈-aralkyl         radical,     -   R² and R³ are independently an optionally branched C₁- to         C₂₂-alkyl radical or an optionally alkyl-substituted C₃- to         C₇-cycloalkyl radical or R² and R³ together form a 2-8-membered         carbon bridge which is optionally substituted by alkyl and/or         interrupted by oxygen atoms,     -   R⁴ is a C₆- to C₁₄-aryl radical optionally substituted by at         least one radical selected from halogen, C₁- to C₄-alkyl,         trifluoromethyl, C₁- to C₄-alkoxy, trifluoromethoxy, phenyl         and/or phenoxy,     -   K is an organocation of valency n and having any substitution,         based on nitrogen, phosphorus, oxygen, sulfur and/or iodine,     -   M is any metal selected from the alkali metals, magnesium,         calcium and aluminium,     -   X is a halide or alkoxide or alkyl sulfide,     -   Y is iodine or bromine or chlorine,     -   n is 1, 2 or 3 and     -   S is an aprotic organic solvent or a mixture of aprotic organic         solvents.

In this process, addition of 3 equivalents of a haloaromatic R⁴—Y (II) to the 3 equivalents of metal initially charged results in in situ generation of an organometallic reagent that reacts with the initially charged substances (I) and (II) to give the triaryl organoborate 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV). It has been found that, surprisingly, the use of substituted organocations of valency n based on nitrogen, phosphorus, oxygen, sulfur and/or iodine as cations has an advantageous effect on the reaction, since they are chemically inert and the reaction proceeds with a higher space-time yield than known processes and fewer side reactions occur and hence the yield is increased and a higher purity of the target product is very much more easily achievable.

Also found to be advantageous is the workup by addition of water and optionally of a further solvent, since the desired triaryl organoborates of the formula 1/n K^(n+) R₃ ⁴B⁻—R¹ (IV) remain in the organic phase and the resulting metals salts MY (OR²), MY (OR³) and MXY can be separated off easily with the aqueous phase.

The inventive triaryl organoborates of formula IV are preferably triaryl(alkyl)borates, triaryl(cycloalkyl)borates, triaryl(alkenyl)borates, triaryl(alkynyl)borates and/or triaryl(aralkyl)borates, more preferably triaryl(alkyl)borates and/or triaryl(cycloalkyl)borates.

The invention therefore likewise provides a process for preparing compounds of the formula 1/n K^(n+) R₃ ⁴B⁻—R¹ (IV),

comprising the steps of

-   -   i) initially charging one equivalent of organoboronic ester         B—R¹(OR²)(OR³) (I) together with 1/n equivalents of salt         K^(n+)nX⁻ (II) and 3 equivalents of metal M in a solvent or         solvent mixture S, and     -   ii) adding 3 equivalents of a haloaromatic R⁴—Y (III), as a         result of which     -   iii) an organometallic reagent generated in situ reacts with the         initially charged substances (I) and (II) to give 1/n K^(n+) R₃         ⁴B⁻—R¹ (IV).     -   This may be followed by the steps of     -   iv) adding water and optionally a further solvent, and     -   v) separating off the desired triaryl organoborates of the         formula 1/n K^(n+) R₃ ⁴B⁻—R¹ (IV) with the organic phase.

This reaction conforms to the following overall reaction equation:

Preferably, R¹ is an optionally hydroxyl- and/or alkoxy- and/or acyloxy- and/or halogen-substituted C₂- to C₁₈-alkyl, C₃- to C₁₈-alkenyl, C₃- to C₁₈-alkynyl, C₅- to C₆-cycloalkyl or C₇- to C₁₃-aralkyl radical and, more preferably, R¹ is an optionally hydroxyl- and/or alkoxy- and/or acyloxy- and/or halogen-substituted C₄- to C₁₆-alkyl, C₃- to C₁₆-alkenyl, C₃- to C₁₆-alkynyl, cyclohexyl or C₇- to C₁₃-aralkyl radical.

Preferably, R² and R³ are independently an optionally branched C₂- to C₁₈-alkyl radical or R² and R³ together form a 4-7-membered, optionally substituted carbocycle and, more preferably, R² and R³ are independently an optionally branched C₃- to C₂-alkyl radical or R² and R³ together form a 4-6-membered, optionally substituted carbocycle.

Preferably, R⁴ is a C₆- to C₁₀-aryl radical optionally substituted by at least one radical selected from halogen, C₁- to C₄-alkyl, trifluoromethyl, C₁- to C₄-alkoxy, trifluoromethoxy, phenyl and/or phenoxy and, more preferably, R⁴ is a C₆-aryl radical optionally substituted by at least one radical selected from halogen, C₁- to C₄-alkyl, trifluoromethyl, C₁- to C₄-alkoxy, trifluoromethoxy, phenyl and/or phenoxy.

An organocation K of valency n based on nitrogen and having any substitution is understood to mean, for example, ammonium ions, pyridinium ions, pyridazinium ions, pyrimidinium ions, pyrazinium ions, imidazolium ions, 1H-pyrazolium ions, 3H-pyrazolium ions, 4H-pyrazolium ions, 1-pyrazolinium ions, 2-pyrazolinium ions, 3-pyrazolinium ions, imidazolinium ions, thiazolium ions, 1,2,4-triazolium ions, 1,2,3-triazolium ions, pyrrolidinium ions, quinolinium ions, which optionally bear further functional groups such as ethers, esters, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form. Preferred organocations K of valency n based on nitrogen are, for example, ammonium ions, pyridinium ions, pyridazinium ions, pyrimidinium ions, pyrazinium ions, imidazolium ions, pyrrolidinium ions, which optionally bear further functional groups such as ethers, esters, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form. Particularly preferred organocations K of valency n based on nitrogen are, for example, ammonium ions, pyridinium ions and imidazolium ions, which optionally bear further functional groups such as ethers, esters, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form. Polymeric cations may also be included within the meaning of the abovementioned substitution patterns.

An organocation K of valency n based on phosphorus and having any substitution is understood to mean, for example, phosphorus(IV) compounds of coordination number 4, for example tetraalkylphosphonium, trialkylarylphosphonium, dialkyldiarylphosphonium, alkyltriarylphosphonium, trialkylenearylphosphonium, dialkylenediarylphosphonium, alkylenetriarylphosphonium or tetraarylphosphonium salts having any substitution, which optionally bear further functional groups such as ethers, esters, carbonyls, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form. Likewise encompassed are 5- to 8-membered aliphatic, quasi-aromatic or aromatic cyclic compounds containing 1, 2 or 3 phosphonium(IV) atoms which may then be substituted by any alkyl or aryl substituents to establish the tetravalency of the phosphorus atom. Aromatic radicals may additionally bear any number of halogen atoms or nitro, cyano, trifluoromethyl, ester and/or ether substituents. It is of course possible for the alkyl and aryl radicals to be bridged to one another by carbon chains or mono- and/or polyether chains, and these then form mono- or polycyclic structures. Preferred organocations K of valency n based on phosphorus are, for example, tetraalkylphosphonium, trialkylarylphosphonium, alkyltriarylphosphonium, dialkyldiarylphosphonium or tetraarylphosphonium salts having any substitution, which optionally bear further functional groups such as carbonyls, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form. Aromatic radicals may additionally bear any number of halogen atoms or ester and/or ether substituents. It is of course possible for the alkyl and aryl radicals to be bridged to one another by carbon chains or mono- and/or polyether chains, and these then form mono- or polycyclic structures. Particularly preferred organocations K of valency n based on phosphorus are, for example, tetraalkylphosphonium, trialkylarylphosphonium, dialkyldiarylphosphonium, alkyltriarylphosphonium or tetraarylphosphonium salts having any substitution, which optionally bear further functional groups such as carbonyls, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form. Aromatic radicals may additionally bear any number of halogen atoms. It is of course possible for the alkyl and aryl radicals to be bridged to one another by carbon chains or mono- and/or polyether chains, and these then form mono- or polycyclic structures. Polymeric cations as specified, for example, in U.S. Pat. No. 3,125,555 may be included within the meaning of the abovementioned substitution patterns.

An organocation K of valency n based on oxygen and having any substitution is understood to mean, for example, pyrylium having any substitution, including in fused form as in benzopyrylium, flavylium naphthoxanthenium. Preferred organocations K of valency n based on oxygen and having any substitution are, for example, pyrylium having any substitution, including in fused form as in benzopyrylium, flavylium. Polymeric cations may also be included within the meaning of the abovementioned substitution patterns.

An organocation K of valency n based on sulfur and having any substitution is understood to mean onium compounds of sulfur that bear identical or different optionally substituted C₁- to C₂₂-alkyl, C₆- to C₄-aryl, C₇- to C₁₅-arylalkyl or C₅- to C₇-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give sulfonium salts with 1≤n≤3. Likewise encompassed are 5- to 8-membered aliphatic, quasi-aromatic or aromatic cyclic compounds containing 1 or 2 sulfonium(III) atoms which may then be substituted by any alkyl or aryl substituents to establish the trivalency of the sulfur atom. Preferred organocations K of valency n based on sulfur are onium compounds of sulfur that bear identical or different optionally substituted C₄- to C₁₄-alkyl, C₆- to C₁₀-aryl, C₇- to C₁₂-arylalkyl or C₅- to C₆-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give sulfonium salts with 1≤n≤3, and also thiopyrylium. Particularly preferred organocations K of valency n based on sulfur are onium compounds of sulfur that bear identical or different optionally substituted C₆- to C₁₂-alkyl, C₆- to C₁₀-aryl, C₇- to C₁₂-arylalkyl or C₅- to C₆-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give sulfonium salts with 1≤n≤3, and also thiopyrylium. Polymeric cations may also be included within the meaning of the abovementioned substitution patterns.

An organocation K of valency n based on iodine and having any substitution is understood to mean onium compounds of iodine that bear identical or different optionally substituted C₁- to C₂₂-alkyl, C₆- to C₁₄-aryl, C₇- to C₁₅-arylalkyl or C₅- to C₇-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give iodonium salts with 1≤n≤3. Preferred organocations K of valency n based on iodine are onium compounds of iodine that bear identical or different optionally substituted C₄- to C₁₄-alkyl, C₆- to C₁₀-aryl, C₇- to C₁₂-arylalkyl or C₅- to C₆-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give iodonium salts with 1≤n≤3. Particularly preferred organocations K of valency n based on iodine are onium compounds of iodine that bear identical or different optionally substituted C₄- to C₁₂-alkyl, C₆- to C₁₀-aryl, C₇- to C₁₂-arylalkyl or C₅- to C₆-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give iodonium salts with 1≤n≤3. Polymeric cations may also be included within the meaning of the abovementioned substitution patterns.

It is additionally possible to use mixtures of the abovementioned cations.

An aprotic organic solvent or a mixture of aprotic organic solvents S is understood to mean solvents that are not deprotonatable without strong bases (Reichardt, C., Solvents and Solvent Effects in Organic Chemistry, 3rd ed.; Wiley-VCH: Weinheim, (2003)). Examples of aprotic organic solvents are alkanes, alkenes, alkynes, benzene and aromatics having aliphatic and/or aromatic substituents, carboxylic esters and/or ethers. Preferred aprotic organic solvents are alkanes, aromatics having aliphatic and/or aromatic substituents and/or ethers. Examples of those used include aromatic hydrocarbons such as solvent naphtha, toluene or xylene, or ethers such as tetrahydrofuran, methyltetrahydrofuran, diethyl ether or dimethoxyethane. The solvent should be very substantially anhydrous. In a preferred embodiment, the first solvent or solvent mixtures (step i) is different from the second solvent or solvent mixture (step iv) that is used in the process. In a preferred embodiment, the same solvents or solvent mixtures are used in step (i) and step (iv).

Preferably, M is magnesium, calcium or aluminium and, more preferably, M is magnesium.

Preferably, X is a halide or alkoxide, X is more preferably a halide and X is especially preferably chloride or bromide.

Preferably, Y is bromine or chlorine and, more preferably, Y is bromine.

Preferably, n is 1 or 2 and, more preferably, n is 1.

In the context of the invention, C₁-C₂₂-alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1,2-dimethylpropyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl or 1-ethyl-2-methylpropyl, n-heptyl, n-octyl, 2-ethylhexyl, pinacyl, n-nonyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, n-docosyl. The same applies to the corresponding alkyl radical, for example in aralkyl/alkylaryl, alkylphenyl or alkylcarbonyl radicals.

Alkylene radicals in substituted alkyl radicals and alkenyl radicals or alkynyl radicals are, for example, the alkylene radicals, alkenyl radicals or alkynyl radicals corresponding to the preceding alkyl radicals.

Examples are 2-chloroethyl, benzyl, allyl, 2-buten-1-yl, propargyl.

In the context of the invention, cycloalkyl is, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl or the isomeric menthyls.

Aryl is a carbocyclic aromatic radical having 6 to 14 skeletal carbon atoms. The same applies to the aromatic moiety of an arylalkyl radical, also known as an aralkyl radical, and to aryl constituents of more complex groups, for example arylcarbonyl radicals.

Examples of C₆- to C₁₄-aryl are phenyl, o-, p-, m-tolyl, o-, p-, m-ethylphenyl, naphthyl, phenanthrenyl, anthracenyl, fluorenyl, o-, p-, m-fluorophenyl, o-, p-, m-chlorophenyl, o-, p-, m-methoxyphenyl, o-, p-, m-trifluoromethylphenyl, o-, p-, m-trifluoromethoxyphenyl, o-, m- or p-biphenylyl, o-, p-, m-phenoxyphenyl, 3,4-dimethylphenyl, 3,4-dichlorophenyl, 3,4-difluorophenyl, 3,4-dimethoxyphenyl, 4-methyl-3-fluorophenyl, 4-methyl-3-chlorophenyl, 3,4,5-trifluorophenyl.

Arylalkyl and aralkyl are each independently a straight-chain, cyclic, branched or unbranched alkyl radical as defined above, which may be mono-, poly- or persubstituted by aryl radicals as defined above.

Examples are benzyl, 4-chlorobenzyl, phenethyl, 2-phenyl-1-propyl, 3-phenyl-1-propyl, 1-phenyl-2-propyl, diphenylmethyl.

Examples of a 2-8-membered carbon bridge optionally substituted by alkyl and/or interrupted by oxygen atoms are —CH₂—CH₂—, —CH₂CH—CH₂—, —CH₂—CH₂—CH₂—CH₂—, —CH₂—CH₂—O—CH₂—CH₂—, —CH₂—CH(CH₃)—.

Examples of a 4-14-membered carbon tricycle optionally substituted by alkyl or aryl and/or interrupted by oxygen atoms are:

The reaction is generally executed without employment of elevated pressure. In that case, the pressure employed in practice will thus at least be the autogenous pressure.

The reaction is generally conducted at temperatures of −20° C. to 100° C., preferably of −10° C. to 80° C., more preferably of 0° C. to 70° C. and especially preferably of 10° C. to 65° C.

In practice, the reaction is started by addition of a maximum of 10% of the total amount of the compound (III), and the compound (III) is then added as a 10%-90%, preferably 15%-75%, more preferably 20%-50%, solution in the solvent S, in the course of which the temperature T varies within the range described above and the reaction can be kept under exothermic control by uniform metered addition of the compound (III). For start-up of the reaction, it is additionally optionally possible to use the compounds known to those skilled in the art such as dibromoethane or iodine, or to activate the metal surface M by means of ultrasound.

It is advantageous to ensure good mixing of the mixture over the entire duration of the reaction, for example by stirring, and to enable good starting of the reaction through choice of a suitable solvent.

By means of the process according to the invention, distinctly better yields are obtained compared to the known processes, for example yields that are at least one-and-a-half times as high.

The invention likewise provides the triaryl organoborates preparable or prepared by the process according to the invention. The triaryl organoborates thus obtainable or obtained additionally preferably contain <10 000 ppm of a tetraarylborate R₄ ³B⁻, more preferably <5000 ppm of a tetraarylborate R₃ ⁴B⁻ and especially preferably <1000 ppm of a tetraarylborate R₄ ³B⁻. The unit ppm is based on parts by weight. The presence of tetraarylborates R₄ ³B⁻, in the case of prolonged storage, leads to limited writability of unexposed photopolymer films comprising the triaryl organoborates according to the invention or loss of the holographic properties in unexposed photopolymer films.

The invention further provides for the use of the triaryl organoborates prepared in accordance with the invention in photoinitiator systems, and also photopolymer compositions comprising a photopolymerizable component and a photoinitiator system comprising the triaryl organoborates prepared in accordance with the invention. Furthermore, holographic media and holograms obtainable therefrom are obtainable from the photopolymer compositions mentioned.

Suitable matrix polymers of a corresponding photopolymer formulation may especially be in a crosslinked state and more preferably in a three-dimensionally crosslinked state.

It is also advantageous for the matrix polymers to be polyurethanes, in which case the polyurethanes may be obtainable in particular by reacting at least one polyisocyanate component a) with at least one isocyanate-reactive component b).

The polyisocyanate component a) preferably comprises at least one organic compound having at least two NCO groups. These organic compounds may especially be monomeric di- and triisocyanates, polyisocyanates and/or NCO-functional prepolymers. The polyisocyanate component a) may also contain or consist of mixtures of monomeric di- and triisocyanates, polyisocyanates and/or NCO-functional prepolymers.

Monomeric di- and triisocyanates used may be any of the compounds that are well known to the person skilled in the art or mixtures thereof. These compounds may have aromatic, araliphatic, aliphatic or cycloaliphatic structures. In minor amounts, the monomeric di- and triisocyanates may also comprise monoisocyanates, i.e. organic compounds having one NCO group.

Suitable prepolymers contain urethane and/or urea groups, and optionally further structures formed through modification of NCO groups as specified above. Prepolymers of this kind are obtainable, for example, by reaction of the abovementioned monomeric di- and triisocyanates and/or polyisocyanates al) with isocyanate-reactive compounds b1).

Isocyanate-reactive compounds b1) used may be alcohols or amino or mercapto compounds, preferably alcohols. These may especially be polyols. Most preferably, the isocyanate-reactive compound b1) used may be polyester polyols, polyether polyols, polycarbonate polyols, poly(meth)acrylate polyols and/or polyurethane polyols.

It is likewise possible to use amines as isocyanate-reactive compounds b1). Examples of suitable amines are ethylenediamine, propylenediamine, diaminocyclohexane, 4,4′-dicyclohexylmethanediamine, isophoronediamine (IPDA), difunctional polyamines, for example the Jeffamines®, amine-terminated polymers, especially having number-average molar masses ≤10 000 g/mol. Mixtures of the aforementioned amines may likewise be used.

It is likewise possible to use amino alcohols as isocyanate-reactive compounds b1). Examples of suitable amino alcohols are the isomeric aminoethanols, the isomeric aminopropanols, the isomeric aminobutanols and the isomeric aminohexanols or any desired mixtures thereof.

All the aforementioned isocyanate-reactive compounds b1) can be mixed with one another as desired.

It is also preferable when the isocyanate-reactive compounds b1) have a number-average molar mass of ≥200 and ≤10 000 g/mol, further preferably ≥500 and ≤8000 g/mol and most preferably ≥800 and ≤5000 g/mol. The OH functionality of the polyols is preferably 1.5 to 6.0, more preferably 1.8 to 4.0.

The prepolymers of the polyisocyanate component a) may especially have a residual content of free monomeric di- and triisocyanates of <1% by weight, more preferably <0.5% by weight and most preferably <0.3% by weight.

It may also be possible for the polyisocyanate component a) to contain, in full or in part, an organic compound wherein the NCO groups have been wholly or partly reacted with blocking agents known from coating technology. Examples of blocking agents are alcohols, lactams, oximes, malonic esters, pyrazoles and amines, for example butanone oxime, diisopropylamine, diethyl malonate, ethyl acetoacetate, 3,5-dimethylpyrazole, e-caprolactam, or mixtures thereof.

It is particularly preferable when the polyisocyanate component a) comprises compounds having aliphatically bonded NCO groups, where aliphatically bonded NCO groups are understood to mean those groups bonded to a primary carbon atom. The isocyanate-reactive component b) preferably comprises at least one organic compound having an average of at least 1.5 and preferably 2 to 3 isocyanate-reactive groups. In the context of the present invention, isocyanate-reactive groups are preferably considered to be hydroxyl, amino or mercapto groups.

The isocyanate-reactive component may especially comprise compounds having a numerical average of at least 1.5 and preferably 2 to 3 isocyanate-reactive groups.

Suitable polyfunctional isocyanate-reactive compounds of component b) are, for example, the above-described compounds b1).

In a further preferred embodiment, the writing monomer c) comprises or consists of at least one monofunctional and/or one multifunctional writing monomer. Further preferably, the writing monomer may comprise or consist of at least one monofunctional and/or one multifunctional (meth)acrylate writing monomer. Most preferably, the writing monomer may comprise or consist of at least one monofunctional and/or one multifunctional urethane (meth)acrylate.

Photoinitiators of component d) are typically compounds activatable by actinic radiation that can trigger polymerization of the writing monomers. The photoinitiators can be distinguished between unimolecular (type I) and bimolecular (type II) initiators. In addition, they are distinguished in terms of their chemical nature into photoinitiators for free-radical, anionic, cationic or mixed modes of polymerization.

Type I photoinitiators (Norrish type I) for free-radical photopolymerization form free radicals on irradiation through unimolecular bond scission. Examples of type 1 photoinitiators are triazines, oximes, benzoin ethers, benzil ketals, bisimidazoles, aroylphosphine oxides, sulfonium salts and iodonium salts.

Type II photoinitiators (Norrish type II) for free-radical polymerization consist of a dye as sensitizer and a co-initiator, and undergo a bimolecular reaction on irradiation with light matched to the dye. The dye at first absorbs a photon and transmits energy to the co-initiator from an excited state. The latter releases the polymerization-triggering free radicals through electron or proton transfer or direct hydrogen abstraction.

In the context of this invention, preference is given to using type 11 photoinitiators.

Photoinitiator systems of this kind are described in principle in EP 0 223 587 A and preferably consist of a mixture of one or more dyes with the inventive compounds of the formula (IV).

Suitable dyes which form a type II photoinitiator together with a compound of the formula (IV) are the cationic dyes described in WO 2012062655, in combination with the anions that have just been described therein.

The triaryl alkyl borates according to the invention are advantageously used aws co-initiators.

The photoinitiator system may also contain a further co-initiator, for example trichloromethyl initiators, aryl oxide initiators, bisimidazole initiators, ferrocene initiators, aminoalkyl initiators, oxime initiators, thiol initiators or peroxide initiators.

In a further preferred embodiment, the photopolymer formulation additionally contains urethanes as additives, in which case the urethanes may especially be substituted by at least one fluorine atom.

The present invention further provides a photopolymer comprising a photopolymer formulation, especially comprising matrix polymers, a writing monomer and a photoinitiator system comprising a compound obtainable or obtained by the process according to the invention.

A holographic medium likewise becomes obtainable, especially in the form of a film comprising a photopolymer according to the invention or obtainable by using a photopolymer formulation according to the invention. The photopolymer composition is also usable for production of holographic media.

It is possible to expose holographic information into such a holographic medium.

The holographic media according to the invention can be processed by corresponding exposure processes for optical applications throughout the entire visible and near-UV range (300-800 nm) to give holograms. Visual holograms include all holograms that can be recorded by processes known to those skilled in the art. These include in-line (Gabor) holograms, off-axis holograms, full-aperture transfer holograms, white light transmission holograms (“rainbow holograms”), Denisyuk holograms, off-axis reflection holograms, edge-lit holograms and holographic stereograms. Preference is given to reflection holograms, Denisyuk holograms, transmission holograms.

Possible optical functions of the holograms which can be produced with the photopolymer formulations according to the invention correspond to the optical functions of light elements such as lenses, mirrors, deflecting mirrors, filters, diffuser lenses, diffraction elements, diffusers, light guides, waveguides, projection lenses and/or masks. It is likewise possible for combinations of these optical functions to be combined in one hologram independently of each other. Frequently, these optical elements exhibit frequency selectivity, according to how the holograms have been exposed and the dimensions of the hologram.

In addition, it is also possible by means of the holographic media to produce holographic images or diagrams, for example for personal portraits, biometric representations in security documents, or generally images or image structures for advertising, security labels, brand protection, branding, labels, design elements, decorations, illustrations, collectible cards, pictures and the like, and pictures that can represent digital data, including in combination with the products detailed above. Holographic images can have the impression of a three-dimensional image, or else they can represent image sequences, short films or a number of different objects, according to the angle from which and the light source with which (including moving light sources) etc. they are illuminated. Because of this variety of possible designs, holograms, especially volume holograms, constitute an attractive technical solution for the abovementioned application.

The holographic media can be used for recording of in-line, off-axis, full-aperture transfer, white light transmission, Denisyuk, off-axis reflection or edge-lit holograms and also of holographic stereograms, especially for production of optical elements, images or image representations.

Holograms are obtainable from the holographic media according to the invention.

The examples which follow serve to illustrate the invention, without restricting it thereto.

EXAMPLES

Test methods:

-   OH number: The OH numbers reported were determined according to DIN     53240-2. -   NCO value: The NCO values (isocyanate contents) reported were     determined according to DIN EN ISO 11909. -   Solids content: The solids contents reported were determined     according to DIN EN ISO 3251. -   Refractive index modulation Δn: The holographic properties Δn of the     holographic media were determined by means of twin-beam interference     in reflection arrangement as described in WO2015091427; a     representative result is shown in FIG. 1.

Substances:

The solvents, reagents and all bromoaromatics used were purchased from chemical suppliers. Anhydrous solvents contain <50 ppm of water.

Ethylboronic acid [82954-89-0] is available from TCI Europe N.V., pinacol ester Zwijndrecht, Belgium. Isopropylboronic acid [76347-13-2] is available from ABCR GmbH & pinacol ester Co. KG, Karlsruhe, Germany. 2-Isopropenylboronic [126726-62-3] is available from ABCR GmbH & acid pinacol ester Co. KG, Karlsruhe, Germany. 1-Dodecylboronic [177035-82-4] is available from ABCR GmbH & acid pinacol ester Co. KG, Karlsruhe, Germany. 3-Phenyl-1-propyl- [329685-40-7] is available from ABCR GmbH & boronic acid Co. KG, Karlsruhe, Germany. pinacol ester Diisopropyl [51851-79-7] is available from ABCR GmbH & allyl boronate Co. KG, Karlsruhe, Germany. (1,3,2-Dioxaborinan- [30169-75-6] is available from ABCR GmbH & 2-yl)cyclohexane Co. KG, Karlsruhe, Germany.

Dibromoborane-dimethyl [55671-55-1] is available from Aldrich Chemie, Steinheim, Germany, sulfide complex

1-Octadecene [112-41-4] is available from ABCR GmbH & Co. KG, Karlsruhe, Germany. Desmorapid Z dibutyltin dilaurate [77-58-7], product from Covestro AG, Leverkusen, Germany. Desmodur ® N 3900 product from Covestro AG, Leverkusen, DE, hexane diisocyanate-based polyisocyanate, proportion of iminooxadiazinedione at least 30%, NCO content: 23.5%. Fomrez UL 28 Urethanization catalyst, commercial product of Momentive Performance Chemicals, Wilton, CT, USA.

2-Hexyl-1,3,2-dioxaborinane [86290-24-6] was prepared as described in Organometallics 1983, 2 (10), p. 1311-16, DOI:10.1021/om50004a008 from 1-hexene, propane-1,3-diol and dibromoborane-dimethyl sulfide complex.

2-Octadecyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was prepared analogously to Organometallics 1983, 2 (10), p. 1311-16, DOI:10.1021/om50004a008 from 1-octadecene, propane-1,3-diol and dibromoborane-dimethyl sulfide complex.

Dye 1 (3,7-bis(diethylamino)phenoxazin-5-ium bis(2-ethylhexyl)sulfosuccinate) was prepared as described in WO 2012062655.

Polyol 1 was prepared as described in Polyol 1 in WO2015091427.

Urethane acrylate 1 (phosphorothioyltris(oxybenzene-4,1-diylcarbamoyloxyethane-2,1-diyl) trisacrylate, [1072454-85-3]) was prepared as described in WO2015091427.

Urethane acrylate 2 (2-({[3-(methylsulfanyl)phenyl]carbamoyl}oxy)ethyl prop-2-enoate, [1207339-61-4]) was prepared as described in WO2015091427.

Additive 1, bis(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl)-(2,2,4-trimethylhexane-1,6-diyl)biscarbamate [1799437-41-4] was prepared as described in WO2015091427.

Origin of the 1/n K^(n+) Cations Used:

The 1/n K^(n+) cations specified in Table 1 were purchased from the chemical supplier mentioned or prepared according to the source mentioned or the preparation is described hereinafter.

TABLE 1 Overview of the cations of the formula (II) used Index Name Structure CAS Source K-1 Tetramethylammonium bromide Me₄NBr [64-20-0] 426296, Aldrich K-2 Tetrabutylammonium bromide Bu₄NBr [1643-19-2] 426288, Aldrich K-3 Benzyldimethylhexadecylammonium chloride BnMe₂HexadecylNCl [122-18-9] AB252026, abcr GmbH K-4 Hexadecyltrimethylammonium bromide

[57-09-0] AB117004, abcr GmbH K-5 Benzethonium chloride

[121-54-0] AB131627, abcr GmbH K-6 1-Hexadecyl-3-methylimidazolium chloride

[61546-01-8] AB289677, abcr GmbH K-7 1-Methyl-3-octylimidazolium chloride

[64697-40-1] AB289637, abcr GmbH K-8 1-Dodecyl-3-methylimidazolium chloride

[114569-84-5] AB289681, abcr GmbH K-9 1-Ethyl-3-imidazolium chloride

[81505-35-3] AB289800, abcr GmbH K-10 1-Benzyl-3-hexadecylimidazolium bromide

[1224595-52-1] Fuel Processing Technology (2014), 118, 296-301. K-11 N-Hexadecylpyridinium chloride monohydrate

[6004-24-6] AB117002, abcr GmbH K-12 N-Docosylpyridinium bromide

[80039-83-4] J. Am. Chem. Soc. (2002), 124 (11), 2604-2613. K-13 4-tert-Butyl-1-hexadecylpyridinium chloride

[1702465-32-4] WO 2015055576 A1 K-14 1,1′-[1,3-Phenylenebis(methylene)]bis(pyridinium) dichloride

[84002-71-1] Zhurnal Neorganicheskoi Khimii (1978), 23, (3), 825-6. K-15 N,N,N,N′,N′,N′-Hexaethyl-1,3-benzenedimethane aminium dibromide

[66753-59-1P] Chemische Berichte (1984), 117 (4), 1487-96 K-16 N,N-Dioctadecylpiperidinium chloride

[61550-95-6] J. Am. Chem. Soc. (1955), 77, 485-6. K-17 N-Hexadecyl-N,N-dimethylanilinium bromide

[17695-00-0] Taiwan Kexue (1959), 13, 95-8. K-18 N,N,N,N′,N′,N′-Hexabutylhexamethylenediammonium dibromide

[745829-82-7P] Chemical Engineering Science, 69 (1), 483- 491 K-19 N-(2-(Benzolyloxy)ethyl)-N,N-dimethyloctadecane-1- aminium bromide

[152167-30-1] U.S. Pat. No. 5,194,472 A K-20 N-(2-((2-Ethylhexanoyl)oxy)ethyl)-N,N- dimethylhexadecane-1-aminium bromide

For preparation method see below K-21 N-Benzyl-N,N-dimethtyl-2-(2- (palmitoyloxy)ethoxy)ethane-1-aminium bromide

For preparation method see below K-22 2-(Benzoyloxy)-N,N-dimethyl-N-(2- (palmitoyloxy)ethyl)ethane-1-aminium bromide

For preparation method see below K-23 N-(3-((2-Ethylhexyl)oxy)-3-oxopropyl)-N,N- dimethyloctadecane-1-aminium bromide

For preparation method see below K-24 N-(2-((Hexylcarbamoyl)oxy)ethyl)-N,N- dimethylhexadecane-1-aminium bromide

For preparation method see below K-25 N¹,N¹⁶-Dihexadecyl-N¹,N¹,N¹⁶,N¹⁶,7,7,10-heptamethyl- 4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16- diaminium dibromide

For preparation method see below K-26 N-(2-((((5-(((2- (Hexadecyldimethylammonio)ethoxy)carbonyl)amino)- 1,3,3- trimethylcyclohexyl)methyl)carbamoyl)oxy)ethyl)- N,N-dimethylhexadecane-1-aminium dibromide

For preparation method see below K-27 N,N′(((((Methylenebis(cyclohexane-4,1- diyl))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane- 2,1-diyl))bis(N,N-dimethylhexadecane-1-aminium) dibromide

For preparation method see below K-28 N,N′-(((((4-Methyl-1,3- phenylene)bis(azanediyl))bis(carbonyl))bis(oxy))bis (ethane-2,1-diyl))bis(N,N-dimethylhexadecane-1- aminium) dibromide

[1073535-73-5] For preparation method see below K-29 N,N′-(((((Methylenebis(4,1- phenylene))bis(azanediyl))bis(carbonyl))bis(oxy))bis (ethane-2,1-diyl))bis(N,N-dimethylhexadecane-1- aminium) dibromide

For preparation method see below K-30 N-(2-(2-(Hexylcarbamoyl)oxy)ethoxy)ethyl)-N,N- dimethylhexadecane-1-aminium bromide

For preparation method see below K-31 N¹,N²²-Dihexadecyl-N¹,N¹,N²²,N²²,10,10,13- heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15- diazadocosane-1,22-diaminium dibromide

For preparation method see below K-32 N-(2-(2-(((3-(10,10-Dimethyl-3-oxo-4,7-dioxa-2,10- diazahexacosan-10-ium-1-yl)-3,5,5- trimethylcyclohexyl)carbamoyl)oxy)etboxy)ethyl)- N,N-dimethylhexadecane-1-aminium dibromide

For preparation method see below K-33 N,N′-((((((Methylenebis(cyclohexane-4,1- diyl))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane- 2,1-diyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N- dimethylhexadecane-1-aminium) dibromide

For preparation method see below K-34 N,N′-(((((((4-Methyl-1,3-phenylene)bis(azanediyl))bis- (carbonyl))bis(oxy))bis(ethane-2,1- diyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N- dimethylhexadecane-1-aminium) dibromide

For preparation method see below K-35 N,N′-(((((((Methylenebis(4,1- phenylene))bis(azanediyl))bis(carbonyl))bis(oxy))bis (ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N- dimethylhexadecane-1-aminium) dibromide

For preparation method see below K-36 N¹,N¹,N¹,N³,N³,N³,N⁵,N⁵,N⁵-Nonamethyl-1,35- benzenetrimethanaminium triiodide

88888-13-5 Chem. Ber. 117, 1487-1496 (1984). K-37 N-[2-[2-[2-(Benzoyloxy)ethoxy]ethoxy]ethyl]-N,N- dimethyloctadecane-1-aminium bromide

[215591-20-1] SK 278487 K-38 1-[3-[(2-Ethylhexyl)oxy]-3-oxopropyl]-4- methylpyridinium chloride

[110250-87-8] U.S. Pat. No. 2,857,310 K-39 4-Methyl-1-[2-[(1-oxotetradecyl)oxy]ethyl]pyridinium chloride

[42936-94-7] Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiyai Khimicheskaya Tekhologiya (1973), 16(6), 891. K-40 1-[[3-(4-Methoxyphenyl)-2-oxo-5- oxazolidinyl]methyl]-4-phenyl-pyridinium bromide

[121082-85-7] DE 3723797 K-41 4-Methyl-1-[2-[(1-oxododecyl)amino]ethyl]pyridinium chloride

[15147-43-0] Chemicky Prumysl (1967), 17(2), 67-9. K-42 4,5-Dihydro-1-methyl-3-[2[(1- oxotradecyl)oxy]ethyl]-2-pentadecyl-1H-imidazolium chloride

[131625-89-3] U.S. Pat. No. 4,954,635 K-43 Morpholinium,4,4-bis[2-[[(9Z)-1-oxo-9-octadecen-1- yl]oxy]ethyl]morpholinium chloride

[272462-96-1] WO2000030444 K-100 Tributyltetradecylphosphonium chloride

[81741-28-8] P444(14) Cl, Ionoic Liquids Technologies GmbH K-101 Trihexyltetradecylphosphonium chloride

[258864-54-9] P666(14) Cl, Ionic Liquids Technologies GmbH K-102 Methyltriphenylphosphonium chloride

[1031-15-8] AB349191, abcr GmbH K-103 Triphenylbenzylphosphonium chloride

[1100-88-5] AB113982, abcr GmbH K-104 Tetraphenylphosphonium chloride

[2001-45-8] AB119018, abcr GmbH K-105 Allyltriphenylphosphonium bromide

[1560-54-9] AB121395, abcr GmbH K-106 (2-Oxo-2-phenylethyl)triphenylphosphonium bromide

[6048-29-9] AB233312, abcr GmbH K-200 4-Methyl-2,6-diphenylpyrylium tetrafluoroborate

[2340-23-0] S919802, Aldrich K-201 2,4,6-Triphenylpyrylium tetrafluoroborate

[448-61-3] AB119969, abcr GmbH K-202 2,4,6-Trimethylpyrylium tetrafluoroborate

[773-01-3] AB177250, abcr GmbH K-203 4,4′-Bis(2,6-diphenylpyrylium tetrafluoroborate)

[42559-29-5] S873950, Aldrich K-300 Diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate

[75482-18-7] AB334122, abcr GmbH K-301 Bis(diphenylsulfonium)diphenyl thioether hexafluorophosphate

[74227-35-3] AB134315, abcr GmbH K-302 Diphenyl[4-(phenylthio)phenyl]sulfonium triflate

[111281-12-0] AB231614, abcr GmbH K-303 Mixture of K-300 + K-301 (Cyracure UVI 6990) [104558-95-4] BASF SE, Ludwigshafen, Germany K-304 Tris[4-[(4-acetylphenyl)thio]phenyl]sulfonium tris[(trifluoromethyl)sulfonyl]methanide

[953084-20-3] BASF SE, Ludwigshafen, Germany K-305 2,4,6-Triphenylthiopyrylium perchlorate

[2930-37-2] AKOS001017031, AKos GmbH Austr. 26 Steinen, D-79585 Germany K-400 (4-Methylphenyl)[4,-(2-methylpropyl)phenyliodonium] hexafluorophosphate

[344562-80-7] BASF SE, Ludwigshafen, Germany K-401 Diphenyliodonium chloride

[1483-72-3] AB109613, abcr GmbH K-402 Bis(4-methylphenyl)iodonium hexaflurophosphate

[60565-88-0] AB336755, abcr GmbH K-403 Diphenyleniodonium chloride

[4673-26-1] AB348986, abcr GmbH

Preparation of Commercially Unavailable Cations 1/n K^(n+) N-(2-((2-Ethylhexanoyl)oxy)ethyl)-N,N-dimethylhexadecane-1-aminium bromide (K-20)

5.00 g of N,N-dimethylethanolamine were initially charged in dry chloroform cooled with an ice bath, and 9.12 g of 2-ethylhexanoyl chloride were cautiously added dropwise and the mixture was stirred at room temperature for 30 min. 30 ml of saturated sodium hydrogencarbonate solution were added and the organic solution was extracted with saturated sodium hydrogencarbonate solution until it was chloride-free. Subsequently, the organic phase was washed with 30 ml of water, the solution was dried and the solvent was distilled off under reduced pressure. 10.99 g of amino ester were obtained.

To a solution of 10.99 g of amino ester in 30 ml of acetonitrile were added 15.58 g of 1-bromohexadecane, and the mixture was heated at reflux for 6 h. The solvent was almost completely distilled off under reduced pressure, the precipitated solids were isolated, and 19.33 g of a colourless tacky resin were obtained.

N-Benzyl-N,N-dimethyl-2-(2-(palmitoyloxy)ethoxy)ethane-1-aminium bromide (K-21)

6.00 g of N,N-2-[2-(dimethylamino)ethoxy]ethanol were initially charged in dry chloroform cooled with an ice bath, and 12.38 g of hexadecanoyl chloride were cautiously added dropwise and the mixture was stirred at room temperature for 30 min. 30 ml of saturated sodium hydrogencarbonate solution were added and the organic solution was extracted with saturated sodium hydrogencarbonate solution until it was chloride-free. Subsequently, the organic phase was washed with 30 ml of water, the solution was dried and the solvent was distilled off under reduced pressure. 14.68 g of amino ester were obtained.

To a solution of 14.68 g of amino ester in 30 ml of acetonitrile were added 6.77 g of benzyl bromide, and the mixture was heated at reflux for 6 h. The solvent was almost completely distilled off under reduced pressure, the precipitated solids were isolated, and 8.23 g of a colourless tacky resin were obtained.

2-(Benzoyloxy)-N,N-dimethyl-N-(2-(palmitoyloxy)ethyl)ethane-1-aminium bromide (K-22)

6.00 g of N,N-2-[2-(dimethylamino)ethoxy]ethanol were initially charged in dry chloroform cooled with an ice bath, and 12.38 g of hexadecanoyl chloride were cautiously added dropwise and the mixture was stirred at room temperature for 30 min. 30 ml of saturated sodium hydrogencarbonate solution were added and the organic solution was extracted with saturated sodium hydrogencarbonate solution until it was chloride-free. Subsequently, the organic phase was washed with 30 ml of water, the solution was dried and the solvent was distilled off under reduced pressure. 14.68 g of amino ester were obtained.

To a solution of 14.68 g of amino ester in 30 ml of acetonitrile were added 6.77 g of benzyl bromide, and the mixture was heated at reflux for 6 h. The solvent was almost completely distilled off under reduced pressure, the precipitated solids were isolated, and 8.23 g of a colourless tacky resin were obtained.

N-(3-((2-Ethylhexyl)oxy)-3-oxopropyl)-N,N-dimethyloctadecane-1-aminium bromide (K-23)

To a solution of 10.0 g of N,N-dimethyl-β-alanine 2-ethylhexyl ester ([184244-48-2], prepared as described in U.S. Pat. No. 5,565,290 A) in 30 ml of acetonitrile were added 15.0 g of octadecyl bromide and the mixture was heated at reflux for 6 h. The solvent was almost completely distilled off under reduced pressure, and 24.50 g of a colourless oil were obtained.

N-(2-((Hexylcarbamoyl)oxy)ethyl)-N,N-dimethylhexadecane-1-aminium bromide (K-24)

To a mixture of 29.4 g of hexyl isocyanate and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 20.6 g of N,N-dimethylethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

50.0 g of aminourethane were dissolved in 120 ml of acetonitrile, 70.6 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 15.0 g of a colourless tacky resin were obtained.

N¹,N¹⁶-Dihexadecyl-N¹,N¹,N¹⁶,N¹⁶,7,7,10-heptamethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diaminium dibromide (K-25)

To a mixture of 27.0 g of Vestanat TMDI (product from EVONIK Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 22.9 g of N,N-dimethylethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

11.7 g of aminourethane were dissolved in 50 ml of acetonitrile, 18.3 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 28.0 g of a colourless tacky resin were obtained.

N-(2-((((-((2-(Hexadecyldimethylammonio)ethoxy)carbonyl)amino)-1,3,3-trimethylcyclohexyl)methyl)carbamoyl)oxy)ethyl)-N,N-dimethylhexadecane-1-aminium dibromide (K-26)

To a mixture of 27.7 g of Desmodur I (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 22.2 g of N,N-dimethylethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

11.9 g of aminourethane were dissolved in 50 ml of acetonitrile, 18.1 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 29.3 g of a colourless tacky resin were obtained.

N,N′-(((((Methylenebis(cyclohexane-4,1-diyl))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethylhexadecan-1-aminium) dibromide (K-27)

To a mixture of 29.7 g of Desmodur W (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 20.2 g of N,N-dimethylethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

12.6 g of aminourethane were dissolved in 50 ml of acetonitrile, 17.4 g of l-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 28.9 g of a colourless tacky resin were obtained.

N,N′-(((((4-Methyl-1,3-phenylene)bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethylhexadecan-1-aminium) dibromide (K-28)

To a mixture of 24.7 g of Desmodur T80 (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 10° C., 253 g of N,N-dimethylethanol, and, on completion of addition, the mixture was kept at 60° C. for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

11.0 g of aminourethane were dissolved in 50 ml of acetonitrile, 19.0 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 27.2 g of a colourless tacky resin were obtained.

N,N′-(((((Methylenebis(4,1-phenylene))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethylhexadecane-1-aminium) dibromide (K-29)

To a mixture of 29.2 g of Desmodur MDI (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 10° C., 20.8 g of N,N-dimethylethanol, and, on completion of addition, the mixture was kept at 60° C. for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

12.4 g of aminourethane were dissolved in 50 ml of acetonitrile, 17.6 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 29.2 g of a colourless tacky resin were obtained.

N-(2-(2-((Hexylcarbamoyl)oxy)ethoxy)ethyl)-N,N-dimethylhexadecane-1-aminium bromide (K-30)

To a mixture of 29.4 g of hexyl isocyanate and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 25.6 g of 2-(2-dimethylaminoethoxy)ethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

13.8 g of aminourethane were dissolved in 50 ml of acetonitrile, 16.2 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 25.0 g of colourless solid, m.p. 220-225° C., were obtained.

N¹,N²²-Dihexadecyl-N¹,N¹,N²²,N²²,10,10,13-heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15-diazadocosane-1,22-diaminium dibromide (K-31)

To a mixture of 23.0 g of Vestanat TMDI (product from EVONIK Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 27.9 g of 2-(2-dimethylaminoethoxy)ethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

13.1 g of aminourethane were dissolved in 50 ml of acetonitrile, 16.9 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 27.5 g of a colourless tacky resin were obtained.

N-(2-(2-(((3-(10,10-Dimethyl-3-oxo-4,7-dioxa-2,10-diazahexacosan-10-ium-1-yl)-3,5,5-trimethylcyclohexyl)carbamoyl)oxy)ethoxy)ethyl)-N,N-dimethylhexadecane-1-aminium dibromide (K-32)

To a mixture of 22.7 g of Desmodur I (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 27.2 g of 2-(2-dimethylaminoethoxy)ethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

13.3 g of aminourethane were dissolved in 50 ml of acetonitrile, 16.7 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 29.3 g of a colourless tacky resin were obtained.

N,N′-(((((((Methylenebis(cyclohexane-4,1-diyl))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethylhexadecane-1-aminium) dibromide (K-33)

To a mixture of 24.8 g of Desmodur W (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 60° C., 25.2 g of 2-(2-dimethylaminoethoxy)ethanol, and the mixture was kept at this temperature for 8 h. After cooling to room temperature, 50.0 g of aminourethane were obtained.

13.9 g of aminourethane were dissolved in 50 ml of acetonitrile, 16.1 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 25.9 g of a colourless tacky resin were obtained.

N,N′-(((((((4-Methyl-1,3-phenylene)bis(azanediyl))bis-(carbonyl))bis(oxy))bis(ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethylhexadecane-1-aminium) dibromide (K-34)

To a mixture of 9.90 g of Desmodur T80 (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 10° C., 15.1 g of 2-(2-dimethylaminoethoxy)ethanol, and, on completion of addition, the mixture was kept at 60° C. for 8 h. After cooling to room temperature, 25.0 g of aminourethane were obtained.

12.6 g of aminourethane were dissolved in 50 ml of acetonitrile, 17.4 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 23.1 g of a colourless tacky resin were obtained.

N,N′-(((((((Methylenebis(4,1-phenylene))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethylhexadecane-1-aminium) dibromide (K-35)

To a mixture of 12.1 g of Desmodur MDI (product from COVESTRO Deutschland) and 0.05 g of Desmorapid Z were added dropwise, at 10° C., 12.9 g of 2-(2-dimethylaminoethoxy)ethanol, and, on completion of addition, the mixture was kept at 60° C. for 8 h. After cooling to room temperature, 25.0 g of aminourethane were obtained.

13.8 g of aminourethane were dissolved in 50 ml of acetonitrile, 16.2 g of 1-bromohexadecane were added dropwise and the mixture was heated at reflux for 12 h. The precipitated solids were isolated, washed with cold ether and dried, and 29.4 g of a colourless tacky resin were obtained.

EXAMPLES

Unless noted otherwise, all percentage figures are based on percent by weight.

Preparation Method a) for Triaryl Organoborates with Cations of Valency n=1

10.0 mmol of the specified boronic ester (I; R¹), 30.0 mmol of magnesium turnings and 10.0 mmol of the salt (II) were suspended in a mixture of 3.40 g of anhydrous toluene and 0.73 g of anhydrous tetrahydrofuran in a dry four-neck flask with a mechanical stirrer, thermometer, metal condenser and pressure-equalized dropping funnel under a nitrogen atmosphere, and stirred vigorously for 30 min. The appropriate haloaromatic (III, R⁴) was added to this solution, at first in undiluted form, until the onset of exothermicity signals the start of the reaction. The remaining total amount of 30.6 mmol of haloaromatic was diluted with 10.0 g of anhydrous toluene and 10.0 g of anhydrous tetrahydrofuran and added dropwise at such a rate that the internal temperature does not exceed 45° C. On completion of addition, the reaction mixture was heated at reflux for 1 h or until the dissolution of the magnesium was complete. The resulting suspension was discharged onto 50 g of ice-water, and the resulting solids are isolated, washed with cold water and dried under reduced pressure. Examples 15, 18, 20 and 27 and 46-52 were extracted from the aqueous phase with 100 ml of ethyl acetate, the solvent was distilled off under reduced pressure and the resulting oils were isolated. The isolated yield for Example 1 that was prepared by this method was 2.87 g (72% of theory), whereas Example 1 prepared according to DE 198 50 139 A1 was obtained in a yield of 47% of theory.

The composition of Examples 1-76 and selected physical properties are summarized in Table 2.

TABLE 2 Overview of the compounds of the formula (IV) with n = 1 Feedstocks according to Substituents of formula (IV) K⁺ preparation method a) and characterization Exam- Boronic ester Haloaromatic ¹¹B M.P. ple (I) (III) Salt (II) R¹ R⁴ [δ/ppm] [° C.] 1 ethylboronic acid pinacol ester 1-bromo-4- fluorobenzene K-1 ethyl

−10.2 101-105 2 ethylboronic acid pinacol ester 1-bromo-4- fluorohenzene K-2 ethyl

−10.3 144-149 3 ethylboronic acid pinacol ester 1-bromo-3- chloro-4- methylbenzene K-1 ethyl

−10.3 88-91 4 ethylboronic acid pinacol ester 1-bromo-3- chloro-4- methylbenzene K-2 ethyl

−10.2 120-122 5 isopropylboronic acid pinacol ester 1-bromo-4- fluorobenzene K-2 i-propyl

−10.3 134-138 6 isopropylboronic acid pinacol ester 1-bromo-3- chloro-4- methylbenzene K-2 i-propyl

−8.3 amorphous 7 2- isopropenylboronic acid pinacol ester 1-bromo-3- chloro-4- methylbenzene K-2 2- propenyl

−8.3 amorphous 8 diisopropyl allyl boronate 1-bromo-3 chloro-4- methylbenzene K-1 allyl

−10.6 amorphous 9 diisopropyl allyl boronate 1-bromo-3- chloro-4- methylbenzene K-2 allyl

−10.6 84-88 10 (1,3,2- dioxaborinan-2- yl)cyclohexane 1-bromo-4- fluorobenzene K-1 cyclohexyl

−10.4 59-60 11 (1,3,2- dioxaborinan-2- yl)cyclohexane 1-bromo-4- fluorobenzene K-2 cyclohexyl

−10.3 166-168 12 (1,3,2- dioxaborinan-2- yl)cyclohexane 1-bromo-3- chloro-4- methylbenzene K-2 cyclohexyl

−8.7 175-177 13 2-hexyl-1,3,2- dioxaborinane 1-bromo-4- fluorobenzene K-2 n-hexyl

−10.3 59-60 14 1-dodecylboronic acid pinacol ester 1-bromo-4- fluorobenzene K-2 n-dodecyl

−10.4 amorphous 15 2-octadecyl- 4,4,5,5- tetramethyl- 1,3,2- dioxaborolane 1-bromo-4- fluorobenzene K-2 n-octadecyl

−10.2 oil 16 2-hexyl-1,3,2- dioxaborinane 1-bromo-4- chlorobenzene K-2 n-hexyl

−10.4 80-81 17 1-dodecylboronic acid pinacol ester 1-bromo-4- chlorobenzene K-2 n-dodecyl

−10.3 amorphous 18 2-octadecyl- 4,45,5- tetramethyl- 1,3,2- dioxaborolane 1-bromo-4- chlorobenzene K-2 n-octadecyl

−10.4 oil 19 2-hexyl-1,3,2- dioxaborinane 1-bromo-4- trifluoromethyl benzene K-2 n-hexyl

−9.8 80-82 20 2-octadecyl- 4,4,5,5- tetramethyl- 1,3,2- dioxaborolane 1-bromo-3- chloro-4- methylbenzene K-2 n-octadecyl

−10.2 oil 21 3-phenyl-1- propylboronic acid pinacol ester 1-bromo-4- chlorobenzene K-2 3- phenylpropyl

−10.3 101-105 22 3-phenyl-1- propylboronic acid pinacol ester 1-bromo-4- methoxybenzene K-2 3- phenylpropyl

−10.3 116-118 23 3-phenyl-1- propylboronic acid pinacol ester 1-bromo-3,4,5- trifluorobenzene K-2 3- phenylpropyl

−10.1 78-86 24 3-phenyl-1- propylboronic acid pinacol ester 1-bromo-3- methyl-4- fluorobenzene K-2 3- phenylpropyl

−13.6 85-87 25 3-phenyl-1- propylboronic acid pinacol ester 1-bromo-4- trifluoro- methoxybenzene K-2 3- phenylpropyl

−10.2 101-108 26 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzen K-3 n-hexyl

−10.6 amphorphous 27 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-4 n-hexyl

−10.6 oil 28 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-5 n-hexyl

−10.6 amorphous 29 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-6 n-hexyl

−10.6 amorphous 30 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-7 n-hexyl

−10.6 amorphous 31 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-8 n-hexyl

−10.6 amorphous 32 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-9 n-hexyl

−10.6 amorphous 33 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-10 n-hexyl

−10.6 amorphous 34 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-11 n-hexyl

−10.6 amorphous 35 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-12 n-hexyl

−10.6 amorphous 36 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-13 n-hexyl

−10.6 amorphous 37 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-16 n-hexyl

−10.6 amorphous 38 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-17 n-hexyl

−10.6 amorphous 39 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-19 n-hexyl

−10.6 amorphous 40 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-20 n-hexyl

−10.6 amorphous 41 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-21 n-hexyl

−10.6 amorphous 42 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-22 n-hexyl

−10.6 amorphous 43 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-23 n-hexyl

−10.6 amorphous 44 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-24 n-hexyl

−10.6 amorphous 45 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-30 n-hexyl

−10.6 amorphous 46 1-dodecylboronic acid pinacol ester 1-bromo-4- chlorobenzene K-2 n-dodecyl

−10.3 oil 47 1-dodecylboronic acid pinacol ester 1-bromo-4- methoxybenzene K-2 n-dodecyl

−10.4 oil 48 1-dodecylboronic acid pinacol ester 1-bromo-3,4,5- trifluorobenzene K-2 n-dodecyl

−10.1 oil 49 1-dodecylboronic acid pinacol ester 1-bromo-3- methyl-4- fluorobenzene K-2 n-dodecyl

−10.6 oil 50 1-dodecylboronic acid pinacol ester 1-bromo-4- trifluoro- methoxybenzene K-2 n-dodecyl

−10.8 oil 51 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-100 n-hexyl

−10.6 oil 52 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-101 n-hexyl

−10.6 oil 53 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-102 n-hexyl

−10.6 decomp. 54 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-103 n-hexyl

−10.6 102-105 55 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-104 n-hexyl

−10.6 134-138 56 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-105 n-hexyl

−10.6 145-146 57 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-106 n-hexyl

−10.6 155-159 58 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-200 n-hexyl

−10.4 amorphous 59 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-201 n-hexyl

−10.4 amorphous 60 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-202 n-hexyl

−10.4 amorphous 61 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-300 n-hexyl

−10.6 amorphous 62 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-303 n-hexyl

−10.6 amorphous 63 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-303 n-hexyl

−10.6 amorphous 64 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-304 n-hexyl

−10.6 amorphous 65 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-305 n-hexyl

−10.6 amorphous 66 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-400 n-hexyl

−10.5 amorphous 67 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-401 n-hexyl

−10.5 amorphous 68 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-402 n-hexyl

−10.5 amorphous 69 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-403 n-hexyl

−10.5 amorphous 70 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-37 n-hexyl

−10.5 amorphous 71 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-38 n-hexyl

−10.5 amorphous 72 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-39 n-hexyl

−10.5 amorphous 73 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-40 n-hexyl

−10.5 amorphous 74 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-41 n-hexyl

−10.5 amorphous 75 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-42 n-hexyl

−10.5 amorphous 76 2-hexyl-1,3,2- dioxaborinane 1-bromo-3 chloro-4- methylbenzene K-43 n-hexyl

−10.5 amorphous

Preparation Method b) for Triaryl Organoborates with Cations of Valency n=2

10.0 mmol of the specified boronic ester (I; R¹), 30.0 mmol of magnesium turnings and 5.0 mmol of the salt (II) are suspended in a mixture of 3.40 g of anhydrous toluene and 0.73 g of anhydrous tetrahydrofuran in a dry four-neck flask under a nitrogen atmosphere with a mechanical stirrer, thermometer, metal condenser and pressure-equalized dropping funnel, and stirred vigorously for 30 min. The appropriate haloaromatic (III, R⁴) is added to this solution, at first in undiluted form, until the onset of exothermicity signals the start of the reaction. The remaining total amount of 30.6 mmol of haloaromatic is diluted with 10.0 g of anhydrous toluene and 10.0 g of anhydrous tetrahydrofuran and added dropwise at such a rate that the internal temperature does not exceed 45° C. On completion of addition, the reaction mixture is heated at reflux for 1 h or until the dissolution of the magnesium was complete. The resulting suspension is discharged onto 50 g of ice-water, and the resulting solids are isolated, washed with cold water and dried under reduced pressure.

The composition of Examples 77-91 and selected physical properties are summarized in Table 3.

TABLE 3 Overview of the compounds of the formula (IV) with n = 2 Feedstocks according to Substituents of formula (IV) K⁺ preparation method b) and characterization Boronic ester Haloaromatic ¹¹B M.P. Example (I) (III) Salt (II) R¹ R⁴ [δ/ppm] [° C.] 77 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-14 n-hexyl

−10.6 amorphous 78 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-15 n-hexyl

−10.6 amorphous 79 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-18 n-hexyl

−10.6 amorphous 80 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-25 n-hexyl

−10.6 amorphous 81 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-26 n-hexyl

−10.6 amorphous 82 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-27 n-hexyl

−10.6 amorphous 83 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-28 n-hexyl

−10.6 amorphous 84 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-29 n-hexyl

−10.6 amorphous 85 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-31 n-hexyl

−10.6 amorphous 86 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-32 n-hexyl

−10.6 amorphous 87 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-33 n-hexyl

−10.6 amorphous 88 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-34 n-hexyl

−10.6 amorphous 89 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-35 n-hexyl

−10.6 amorphous 90 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-203 n-hexyl

−10.6 amorphous 91 2-hexyl-1,3,2- dioxaborinane 1-bromo-3- chloro-4- methylbenzene K-301 n-hexyl

−10.6 amorphous

Example 92 (Cation of Valency n=3)

1.70 g of 2-hexyl-1,3,2-dioxaborinane (10.0 mmol; I; R¹=n-hexyl), 0.73 g (30.0 mmol) of magnesium turnings and 2.25 g of N¹,N¹,N¹,N³,N³,N⁵,N⁵,N⁵-nonamethyl-1,3,5-benzentrimethanaminium triiodide (3.33 mmol; K-36; II) are suspended in a mixture of 3.40 g of anhydrous toluene and 0.73 g of anhydrous tetrahydrofuran in a dry four-neck flask having a mechanical stirrer, thermometer, metal condenser and pressure-equalized dropping funnel under a nitrogen atmosphere, and stirred vigorously for 30 min. 1-Bromo-3-chloro-4-methylbenzene (III, R⁴) is added to this solution, at first in undiluted form, until the onset of exothermicity signals the start of the reaction. The remaining total amount of 6.29 g (30.6 mmol) of l-bromo-3-chloro-4-methylbenzene is diluted with 10.0 g of anhydrous toluene and 10.0 g of anhydrous tetrahydrofuran and added dropwise at such a rate that the internal temperature does not exceed 45° C. On completion of addition, the reaction mixture is heated at reflux for 1 h or until the dissolution of the magnesium was complete. The resulting suspension is discharged onto 50 g of ice-water, and the resulting solids are isolated, washed with cold water and dried under reduced pressure.

¹¹B NMR [δ/ppm] −10.6.

Production of Media to Determine the Holographic Properties Example Medium I

3.38 g of the polyol component 1 were mixed with 0.010 g of Example 1, 2.00 g of urethane acrylate 1, 2.00 g of urethane acrylate 2, 1.50 g of additive 1, 0.10 g of triaryl organoborate 1 of formula (IV), 0.010 g of dye 1 and 0.35 g of N-ethylpyrrolidone at 60° C., so as to obtain a clear solution. Subsequently, the mixture was cooled down to 30° C., 0.65 g of Desmodur® N3900 was added and the mixture was mixed again. Finally, 0.01 g of Fomrez UL 28 was added and the mixture was mixed briefly again. The fluid mass obtained was then applied to a glass plate and covered thereon with a second glass plate. This specimen was left to stand at room temperature for 12 hours and hardened.

Example Medium II-XX

The procedure was as in Example medium I, except using 0.10 g of the specified triaryl organoborate of formula (IV) rather than 0.10 g of triaryl organoborate 1. The holographic properties of Example media I-XX are summarized in Table 4.

TABLE 4 Overview of the holographic properties of Example media I-XX Example Example of medium formula (IV) Δn I 1 0.033 II 13 0.029 III 16 0.029 IV 17 0.034 V 18 0.033 VI 19 0.032 VII 20 0.037 VIII 24 0.033 IX 29 0.034 X 45 0.039 XI 51 0.035 XII 52 0.034 XIII 57 0.037 XIV 66 0.038 XV 77 0.037 XVI 79 0.040 XVII 81 0.040 XVIII 85 0.037 XIX 86 0.035 XX 88 0.037

The values found for Example media I to XX show that the compounds of the formula (IV) used in the photopolymer formulations are of very good suitability for use in holographic media. 

1. Process for preparing triaryl organoborates of the formula 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV), where one equivalent of an organoboronic ester of the formula B—R¹(OR²)(OR³) (I) is initially charged together with 1/n equivalents of salt K^(n+)nX⁻ (II) and 3 equivalents of metal M in a solvent or a solvent mixture S, 3 equivalents of a haloaromatic R⁴—Y (III) are added, water and optionally a second organic solvent S is added and the compound 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV) is separated off with the organic phase, and R¹ is an optionally hydroxyl- and/or alkoxy- and/or acyloxy- and/or halogen-substituted C₁- to C₂₂-alkyl, C₃- to C₂₂-alkenyl, C₃- to C₂₂-alkynyl, C₅- to C₇-cycloalkyl or C₇- to C₁₃-aralkyl radical and R² and R³ are independently an optionally branched C₁- to C₂₂-alkyl radical or an optionally alkyl-substituted C₃- to C₇-cycloalkyl radical or R² and R³ together form a 2-8-membered carbon bridge which is optionally substituted by alkyl and/or interrupted by oxygen atoms and R⁴ is a C₆- to C₁₀-aryl radical optionally substituted by at least one radical selected from halogen, C₁- to C₄-alkyl, trifluoromethyl, C₁- to C₄-alkoxy, trifluoromethoxy, phenyl and phenoxy and K is an organocation of valency n and having any substitution, based on nitrogen, phosphorus, oxygen, sulfur and/or iodine, and M is any metal selected from the alkali metals, magnesium, calcium and aluminium and X is a halide or alkoxide or alkyl sulphide and Y is iodine or bromine or chlorine and n is 1, 2 or 3 and S is an aprotic organic solvent or a mixture of aprotic solvents.
 2. Process for preparing compounds 1/n K^(n+)R₃ ⁴B⁻—R¹ of the formula (IV) according to claim 1, comprising the steps of i) initially charging one equivalent of organoboronic ester B—R¹(OR²)(OR³) (I) together with 1/n equivalents of salt K^(n+)nX⁻ (II) and 3 equivalents of metal M in a solvent or solvent mixture S, ii) adding 3 equivalents of a haloaromatic R⁴—Y (III), as a result of which iii) an organometallic reagent generated in situ reacts with the initially charged substances (I) and (II) to give 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV).
 3. Process according to claim 1, characterized in that the organocations K of valency n based on nitrogen are ammonium ions, pyridinium ions and imidazolium ions, which optionally bear further functional groups such as ethers, esters, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form.
 4. Process according to claim 1, characterized in that the organocations K of valency n based on phosphorus are tetraalkylphosphonium, trialkylarylphosphonium, dialkyldiarylphosphonium, alkyltriarylphosphonium or tetraarylphosphonium salts having any substitution, which optionally bear further functional groups such as carbonyls, amides and/or carbamates in one or more side chains and which may also be in oligomeric or polymeric or bridging form.
 5. Process according to claim 1, characterized in that the organocation K of valency n based on oxygen is pyrylium having any substitution, including in fused form as in benzopyrylium, flavylium, naphthoxanthenium or polymeric cations with the substitution patterns mentioned.
 6. Process according to claim 1, characterized in that the organocations K of valency n based on sulfur are onium compounds of sulfur that bear identical or different optionally substituted C₆- to C₁₂-alkyl, C₆- to C₁₀-aryl, C₇- to C₁₂-arylalkyl or C₅- to C₆-cycloalkyl radicals and/or that form oligomeric or polymeric repeating connecting units to give sulfonium salts with 1≤n≤3, and thiopyrylium or polymeric cations with the substitution patterns mentioned.
 7. Process according to claim 1, characterized in that the organocations K of valency n based on iodine are onium compounds of iodine bearing identical or different optionally substituted C₄- to C₁₂-alkyl, C₆- to C₁₀-aryl, C₇- to C₁₂-arylalkyl or C₅- to C₆-cycloalkyl radicals and/or form oligomeric or polymeric repeating connecting units to give iodonium salts with 1≤n≤3, or are further polymeric cations with the substitution patterns mentioned.
 8. Process according to claim 1, characterized in that R¹ is an optionally hydroxyl- and/or alkoxy- and/or acyloxy- and/or halogen-substituted C₂- to C₁₈-alkyl, C₃- to C₁₈-alkenyl, C₃- to C₁₈-alkynyl, C₅- to C₆-cycloalkyl or C₇- to C₁₃-aralkyl radical.
 9. Process according to claim 1, characterized in that R² and R³ are independently an optionally branched C₂- to C₁₈-alkyl radical or R² and R³ together form a 4-7-membered, optionally substituted carbocycle.
 10. Process according to claim 1, characterized in that R⁴ is a C₆- to C₁₀-aryl radical optionally substituted by at least one radical selected from halogen, C₁- to C₄-alkyl, trifluoromethyl, C₁- to C₄-alkoxy, trifluoromethoxy, phenyl and/or phenoxy.
 11. Triaryl organoborates of the formula 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV) obtainable or obtained by the process of claim
 1. 12. Use of the triaryl organoborates of the formula 1/n K^(n+)R₃ ⁴B⁻—R¹ (IV) according to claim 11 in photoinitiator systems.
 13. Photopolymer composition comprising a photopolymerizable component and a photoinitiator system comprising the triaryl organoborates according to claim
 11. 14. Holographic medium comprising a photopolymer composition according to claim
 13. 15. Hologram comprising a holographic medium according to claim
 14. 